Glossary of Astro Terms

[iceman]

If you're new to astronomy and you're wondering what all the technical jargon you read around here really means, then be sure to check out the

Glossary of Terms (http://www.iceinspace.com.au/glossary.html)

on the IceInSpace main site.

If you're still unsure, please don't hestitate to post here and ask!

If you think anything should be added to the glossary, please let me know. Likewise if you find any errors.

Thanks to Ken (ballaratdragons) for compiling the glossary.

[Starkler]

Nice work Ken :thumbsup:

[ballaratdragons]

Thanks guys.

It is a compilation of facts from lots of sites, books, and some I wrote myself.

I tried to keep it simple, mainly using the lingo used in the forum plus a few that may come up.

A full Glossary has thousands of entries, many of which we don't use in here.

I just hope it gets used, then it was worth the effort.

[ving]

well done ken and mike, you guys are leg ends :)

[gaa_ian]

Good on you Ken, this should help clear up a few questions ...
Those, "Ive always wanted to know ..but been afraid to ask questions"

[[1ponders]]

:clap: :clap::clap:

[Moonman]

Some good info on eyepiece design setups.

No doubt will learn more of this as I go along.

Moonman

[Striker]

Thats great but what does Glossary mean......lol

Nice work Ken.....

[Ratman]

Good job, well done. Now I wont have to ask silly questions on my first post!

Cheeers Rats.

[ballaratdragons]

Hi Rattie,

There are no silly questions in here. Ask anything you like!!!

[Ratman]

What makes a 'parabolic' scope different to other scopes? (Just showing my ignorance, forgive me, Im still new at this)
Cheers rats. :confused:

[Ganymede]

Gidday Ratty, Here's my understanding of this; as you may already know light travels in 'waves' of varying wavelengths. Light toward the red end of the spectrum has a longer wavelenth than that at the violet end of the spectrum.

When light enters the telescope and strikes the mirror it is reflected back up the tube (in the case of a reflector type) to a point known as the focal point. A spherical mirror (one which has a surface shaped like part of a perfect sphere) tends to bring light of different wavelengths to slightly different focal points.

This causes an optical effect known as spherical abberation which can lead to unnatural colour casts and an effect called coma, which produces elongated images of points (the stars look like little comets). Using a parabolic mirror (one shaped like a parabola, which is the shape you get if you slice vertically down thru a cone) tends to alleviate these effects by focussing all wavelengths of light at virtually the same focal point.

I understand there are some telescopes with mirrors that have a modified parabolic shape (Meade RCX400 - Ritchey-Chretien) that virtually eliminate these effects altogether BUT they come come with a mind-numbing price tag!

:atom: Hope this helps

[slice of heaven]

Heres a pic to show the difference


http://web.ask.com/fr?u=http%3A%2F%2Fwww.physics.umd.e du%2Flecdem%2Fservices%2Fdemos%2Fde mosl3%2Fl3-24.htm&s=a&bu=http%3A%2F%2Fweb.ask.com%2Fweb%3 Fq%3Dwhat%2Bare%2B%2B%2Bparabolic%2 Bmirrors%26o%3D10234%26page%3D1&q=what+are+++parabolic+mirrors&o=10234&qt=0&ma=PURPOSE%3A%20To%20demonstrate%20 the%20difference%20in%20spherical%2 0aberration%20between%20concave%20s pherical%20and%20parabolic%20mirror s.&mt=L3-24.HTML&mb=
Ask Jeeves Results - what are parabolic mirrors

[Ganymede]

Wow - I've never seen it that graphically demonstrated before!:eyepop:

[Ratman]

Thanks Ganymede and Slice of Heaven, your input has clarified the difference.

Cheeers Rats

[confined]

Beautiful. This is just the kind of stuff I am looking for, as i'm just learning about astronomy.

Thanks iceman :)

[astro_set]

Ken, what a great glossary. Thanks for all the work to help beginners
like me.

[ballaratdragons]

Your welcome Susan.

I used to be confused by the lingo and I remember what it was like not understanding.

Hope it helps!

[acropolite]

Onya Ken, nice work.:D

[hookedonsaturn]

Now this IS helpfull. Only thing is now i have to learn the whole alphabet.Thats why i took up astronomy so i only had to learn 1 letter

[wren3]

People suddenly seem to be making a lot more sense.
Great Work

[troypiggo]

As a newbie getting into astrophotography being confused by all these new terms, this glossary is a great idea.

I have some more terms that aren't on that list that I don't fully understand, although some I do but weren't on the list, and think it'd help others if they are added. Mainly equipment type terms, some are commonly used abbreviations here:

focal reducer
field flattener
guide scope
dew heater
guide cam
goto
SCT
ED
APO
HST
ISS
DSO
first light
piggyback
sub (sub exposures)
dark frame
stacking

That's all I can think of at the moment. I know many of these terms are obvious to you guys, but to a newbie I either didn't know and had to search, or had to think a little harder than normal to figure them out. :o

[Dylan]

These terms would be useful while writing an article or a webcontent regarding astronomy ! great work done !

[telecasterguru]

Thanks for the info, it is a great help for a starter.

[EcoRI]

Hi all,

Its a been a while since I put in a post, I went off and sulked when I didn't win the Ice in Space 5yr comp (joke, joke).

My question is, where is the link to this glossary?

I followed Mike's link on the first post but only got the IIS homepage. I also looked in the articles and could not seem to find it.

Thanks in advance.
Greg

[iceman]

Try here Greg:
http://www.iceinspace.com.au/glossary.html

Cheers

[EcoRI]

Thanks Mike,

Sorry it took so long for me to reply.

Much appreciated,

Greg

[austinstkong]

Agreed, it will be nice to have some more key terms added to the list.

Here are a few more that I think is worth adding

f ratio
focal length
CCD
star trail
rack and pinion/Crayford focuser

[torana68]

and you can google it and save the links to the various existing lists as well as the one on here for example
http://observers.org/beginner/glossary.html

[ballaratdragons]

It is pleasing to see that people are still using the Glossary.
It lets me know it was certainly worth doing :thumbsup:

and yeah, don't forget that you can google any term not in here.

[Binca]

"
AuroraA glow in a planet's ionosphere caused by the interaction between the planet's magnetic field and charged particles from the Sun. This phenomenon is known as the Aurora Borealis in the Earth's northern hemisphere and the Aurora A "

I know the Aurora Ausralis is listed right under, but unless my laptop is just being stupid, may I suggest finishing the sentence? :)

Still, I love the glossary, I think I will find it really useful!

[iceman]

hmm should the Astronomy Acronyms article be combined with the Glossary?

Astronomy Acronyms (and constellation acronyms): http://www.iceinspace.com.au/index.p...63,440,0,0,1,0
Glossary: http://www.iceinspace.com.au/glossary.html

I had an email from someone who wanted some things added to the glossary because they weren't there (APO and ED), and then I found them in this Acronyms article.

Might be worth combining to have an overall source?

Thoughts?

[iceman]

The Glossary has been merged with Astronomy Acronyms and modern constellation abbreviations.

You'll still find it at the same place:

Glossary of Terms of Astronomy Acronyms (http://www.iceinspace.com.au/glossary.html)

I'm happy to add any new terms or acronyms or abbreviations - please just get in touch and send them to me. Ideally with the term/meaning, or if you don't know, I can search it up and then add it :)

[iceman]

The Glossary has been merged with Astronomy Acronyms and modern constellation abbreviations.

You'll still find it at the same place:

Glossary of Terms of Astronomy Acronyms (http://www.iceinspace.com.au/glossary.html)

I'm happy to add any new terms or acronyms or abbreviations - please just get in touch and send them to me. Ideally with the term/meaning, or if you don't know, I can search it up and then add it :)

[Mliss]

Noob bible :2thumbs: Perfect!

Thanks Mike and all those who contributed!

:newbie:

[Grease]

:thanx:

I realise this has been on here for a couple of years but what an awesome list for us newbies.

Do I have to memorise it? Is there a test? :rofl:

Good work and thankyou.

[jeff.cotter]

Good glossary!

[salimant]

?Thanks for sharing, great to know

[CrazyGiza]

VidAstroGoToDob-ology, -ologist

The study of the sky aided by a Dobsonian Telescope with GoTo mechanization and Video Assistance...

Clear skies

[CrazyGiza]

Sounded good but apparently we need shorter focal length...:shrug:.. focal reducers would bring their own cons with the pros.

[GeoffW1]

Hi,

I'm working on an update to this, to send in to Mike.

So, any suggestions for new terms or glaring omissions?

Cheers

[GeoffW1]

Bump - and last call :hi:

[MichaelSW]

Geoff,

I read this in a book just last night. Had to learn what an APPARITION was.

In the course of an 8-year cycle, Venus will be seen to complete ten apparitions (five in the morning and five in the evening), each apparition lasting about 35 weeks (9 months).

Cheers.

[mike.wiseman]

I have seen references to "averted vision" - what is it and how does it work?
Thanks
Mike

[Outcast]

Averted vision is a technique for viewing faint objects which uses peripheral vision. It involves not looking directly at the object, but looking a little off to the side, while continuing to concentrate on the object.

Read more here, quite a few tips on technique:

http://https://en.m.wikipedia.org/wiki/Averted_vision (https://en.m.wikipedia.org/wiki/Averted_vision)

[mike.wiseman]

Thanks for this!


and there was me thinking it had to do with looking away when caught staring at an attractive one of the opposite sex ;-))

[Outcast]

Contextually, that'd be correct too... :rofl:

[BlurredClarity]

This is fantastic. Thanks a lot.

[barwellp]

Thanks very much, this is really helpful.:)